Materials Study of NbN and Ta _x N Thin Films for SNS Josephson Junctions

Journal Article · Tue Feb 14 23:00:00 EST 2017 · IEEE Transactions on Applied Superconductivity

DOI:https://doi.org/10.1109/tasc.2017.2669582· OSTI ID:1356859

Missert, Nancy ^[1]; Brunke, Lyle ^[1]; Henry, Michael D. ^[1]; Wolfley, Steve ^[1]; Howell, Steve ^[1]; Mudrick, John ^[1]; Lewis, Rupert ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

We investigated properties of NbN and Ta_xN thin films grown at ambient temperatures on SiO₂/Si substrates by reactive-pulsed laser deposition and reactive magnetron sputtering (MS) as a function of N₂ gas flow. Both techniques produced films with smooth surfaces, where the surface roughness did not depend on the N₂ gas flow during growth. High crystalline quality, (111) oriented NbN films with T_c up to 11 K were produced by both techniques for N contents near 50%. The low temperature transport properties of the Ta_xN films depended upon both the N₂ partial pressure used during growth and the film thickness. Furthermore, the root mean square surface roughness of Ta_xN films grown by MS increased as the film thickness decreased down to 10 nm.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1356859
• Report Number(s): SAND2017--4568J; 652916
• Journal Information: IEEE Transactions on Applied Superconductivity, Journal Name: IEEE Transactions on Applied Superconductivity Journal Issue: 4 Vol. 27; ISSN 1051-8223
• Publisher: Institute of Electrical and Electronics Engineers (IEEE)
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
NbN
TaN
atomic force microscopy
electronic transport
scanning electron microscopy
superconducting materials
x-ray diffraction